In a normal coal gasification process wherein a particulated carbonaceous fuel such as coal or coke or a carbonaceous gas is burned, the process is carried out at relatively hot temperatures and high pressures. A facility for achieving such a process is generally embodied in a gasifier comprised basically of a steel shell having internally insulated walls. The latter are formed preferably of a refractory which defines the unit combustion chamber.
As injected fuel is burned or partially burned in the combustion chamber, the effluent will be discharged from a port at the lower end of said chamber. It will then enter an adjacently positioned quench chamber to be cooled.
The quench chamber is comprised primarily of a pool formed of a liquid such as water. As the higher temperature effluent contacts and passes through the cooling pool, it will be reduced in temperature as well as pressure. The gas, preferably in saturated condition at about 425.degree. to 450.degree. F., will be conducted from the quench chamber for further processing.
When the fuel is a solid such as coal or coke, this arrangement permits the solid portion of the effluent, in the form of ash, to be retained in the liquid pool, and subsequently to be discharged as a slag slurry. The gaseous component, however, in passing through quench chamber, will carry with it a substantial amount of the liquid coolant.
A minimal amount of liquid entrained in the exiting gas is not considered objectionable to the overall process. However, excessive liquid carried from the quench chamber and into downstream equipment, is found to pose operational problems.
The path of the exiting saturated gas, is defined by baffling placed in the quench chamber. Consequently, as liquid-carrying gas contacts baffle surfaces, a certain amount of the liquid will coalesce on the baffle surfaces. However, the rapidly flowing gas will re-entrain liquid droplets by sweeping them from the baffle's lower edge.
Toward overcoming this undesirable characteristic in a water quenched gasifier unit, there is presently provided means for accumulating and retaining coolant water which has been separated from a produced gaseous stream. The water, after impinging against one of the baffle plates which defines the path of the gaseous stream, is caused to gravitate and accumulate in a manifold, or similar means for retaining the liquid. As the substantially liquid-free gas continues on its path toward the gasifier discharge exit, retained liquid will drain back into the coolant pool.
It is therefore an object of the invention to provide a gasifier of the type contemplated in which the quench chamber is provided with means for retaining cooling liquid which would otherwise be carried from the chamber.
A further object is to provide a gasifier of the type in which the hot produced gas is water cooled, wherein gas directing baffles are provided with a water accumulating facility to redirect water back into the quenching pool.